This invention relates to a novel class of sulfonamides and their use as herbicides and plant growth regulants.
U.S. Pat. No. 4,127,405 teaches compounds which are useful for controlling weeds in wheat having the formula: ##STR1## wherein
R.sub.1 is ##STR2##
R.sub.3 and R.sub.6 are independently hydrogen, fluorine, chlorine, bromine, iodine, alkyl of 1-4 carbon atoms, alkoxy of 1-4 carbon atoms, nitro, trifluoromethyl, cyano, CH.sub.3 S(O).sub.n -- or CH.sub.3 CH.sub.2 S(O).sub.n --;
R.sub.4 is hydrogen, fluorine, chlorine, bromine or methyl;
R.sub.5 is hydrogen, fluorine, chlorine, bromine, methyl or methoxy;
R.sub.7 is hydrogen, fluorine, chlorine, bromine, alkyl of 1-2 carbon atoms or alkoxy of 1-2 carbon atom;
R.sub.8 is hydrogen, methyl, chlorine or bromine;
R.sub.9 and R.sub.10 are independently hydrogen, methyl, chlorine or bromine;
W and Q are independently oxygen or sulfur;
n is 0, 1 or 2;
X is hydrogen, chlorine, bromine, methyl, ethyl, alkoxy of 1-3 carbon atoms, trifluoromethyl, CH.sub.3 S-- or CH.sub.3 OCH.sub.2 --; and
Y is methyl or methoxy; or their agriculturally suitable salts; provided that:
(a) when R.sub.5 is other than hydrogen, at least one of R.sub.3, R.sub.4, R.sub.6 and R.sub.7 is other than hydrogen and at least two of R.sub.3, R.sub.4, R.sub.6 and R.sub.7 must be hydrogen;
(b) when R.sub.5 is hydrogen and all of R.sub.3, R.sub.4, R.sub.6 and R.sub.7 are other than hydrogen, then all of R.sub.3, R.sub.4, R.sub.6 and R.sub.7 must be either chlorine or methyl; and
(c) when R.sub.3 and R.sub.7 are both hydrogen, at least one of R.sub.4, R.sub.5 or R.sub.6 must be hydrogen.
Netherlands Pat. No. 121,788, published Sept. 15, 1966, discloses the preparation of compounds of the following Formula and their use as general or selective herbicides: ##STR3## wherein
R.sub.1 and R.sub.2 may independently be alkyl of 1-4 carbon atoms; and
R.sub.3 and R.sub.4 may independently be hydrogen, chlorine or alkyl of 1-4 carbon atoms.
U.S. Pat. No. 3,637,366 discloses compounds having the formula: ##STR4## wherein
R.sub.1 is hydrogen or lower saturated aliphatic acyl; and
R.sub.2 is hydrogen, 2-pyrimidinyl, pyridyl, amidino, acetyl or carbamoyl.
The disclosed compounds are said to provide control of crabgrass, cress, endive, closer and Poa annua.
French Pat. No. 1,468,747 discloses the following para-substituted phenylsulfonamides, useful as antidiabetic agents: ##STR5## wherein R=H, halogen, CF.sub.3 or alkyl.
Logemann et al., Chem. Ab., 53, 18052g (1959), disclose a number of sulfonamides, including uracil derivatives and those having the formula: ##STR6## wherein R is butyl, phenyl or ##STR7## and R.sub.1 is hydrogen or methyl. When tested for hypoglycemic effect in rats (oral doses of 25 mg/100 g), the compounds in which R is butyl and phenyl were most potent. The others were of low potency or inactive.
Wojciechowski, J. Acta. Polon. Pharm. 19, p. 121-5 (1962) [Chem. Ab., 59 1633 e] describes the synthesis of N-[(2,6-dimethoxypyrimidin-4-yl)aminocarbonyl]-4-methylbenzenesulfonamide: ##STR8## Based upon similarity to a known compound, the author predicted hypoglycemic activity for the foregoing compound.
Substituted-pyrimidinyl sulfonylureas of the following formula, which are also para-substituted on the phenyl ring, are disclosed in Farmco Ed. Sci., 12, 586 (1957) [Chem. Ab., 53, 18052 g (1959)]: ##STR9## wherein R=H or CH.sub.3.
Unexamined European Pat. No. 7687 discloses, among others, herbicidal sulfonylures of the general structure: ##STR10## where
R is H, alkyl, alkenyl, aryl, etc.;
R.sub.6 is H or alkyl; or
R and R.sub.6 can be taken together to form --(CH.sub.2).sub.4, --(CH.sub.2).sub.5 --, --(CH.sub.2).sub.6 --, --CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 -- or --CH.sub.2 CH.sub.2 N(CH.sub.3)CH.sub.2 CH.sub.2 --.
U.S. Ser. No. 209,307, filed Nov. 24, 1980, discloses, among others, herbicidal sulfonylureas of the general structure: ##STR11## where
R is as disclosed in U.S. Ser. No. 029,281, now abandoned; and
R.sub.6 is ##STR12##
The presence of undesired vegetation causes substantial damage to useful crops, especially agricultural products that satisfy man's basic food and fiber needs, such as cotton, rice, corn, wheat, and the like. The current population explosion and concomitant world food shortage demand improvements in the efficiency of producing these crops. Prevention or minimizing the loss of a portion of valuable crops by killing, or inhibiting the growth of undesired vegetation is one way of improving this efficiency. A wide variety of materials useful for killing, or inhibiting (controlling) the growth of undesired vegetation is available; such materials are commonly referred to as herbicides. The need still exists however, for more effective herbicides.